1. Field of the Invention
This invention relates to a composite textile material, in particular of the type that protects against nuclear, radiological, biological and chemical attacks, called N.R.B.C., or else in the military field described as chemical warfare agents, as well as protective items manufactured from said material.
2. Introduction and Prior Art
The protection against the NRBC (nuclear, radiological, biological and chemical) risks requires the use of various protective items (protective clothing, overalls, gloves, socks, hoods, ponchos, covering the body of the user partially or completely, etc., air filtration systems or units . . . ) designed to prevent contact with toxic agents (in liquid or gaseous form) with the skin or mucous membranes of the user. Thus, in the prior art, two ranges of protective items have been developed: those produced from impermeable materials and those using permeable materials.
In the first case, the wearer is completely protected from the outside threat, but his body cannot exchange calories with the outside environment. The extended wearing of this type of clothing therefore leads irremediably to problems of hyperthermia that can become deadly.
To remedy this problem, clothing that uses air-permeable materials has been developed. This clothing uses a set of textile materials that comprise several layers that consist in general of an outer layer—on the side of the environment outside of the user—, a layer of filter material, and an inner layer—on the side of the user—, with the following characteristics and functions:
The outer layer: it consists of an outer textile whose primary functions are to ensure the sturdiness of the clothing—resistance to abrasion and tearing—and to ensure the non-penetration of attacker agents in liquid form. This non-penetration is generally achieved by the application of a hydrophobic and oleophobic treatment on the outer textile, as described in, for example, the document FR-A-2 678 172.
The layer of filter material: it ensures the filtration of toxins in gaseous form owing to the adsorbent carbon particles that it contains. The activated carbon particles are in general bonded to a textile substrate or to a non-woven substrate. As examples of these technologies, it is possible to consider:
The impregnated foams of activated carbon powder as described in the documents FR-A-2,678,172; U.S. Pat. No. 5,277,963 and the activated carbon balls that are bonded to a textile as described in U.S. Pat. No. 5,334,436.
The filter material layer can also come in the form of an activated carbon tissue as taught in U.S. Pat. No. 5,731,065.
The inner layer: it consists of a preferably flexible textile and ensures the comfort of the wearer by preventing direct contact of the filter material with the skin. It also plays a role in the storage of sweat.